Known comminution apparatus, particularly document shredders, generally have oppositely running cutting rolls with cutting discs intersecting with one another which act in the manner of a longitudinal cutter and which cut the material to be cut into long strips the width of which corresponds to the thickness of the discs. In order that the rollers better grasp the material to be comminuted, the cutting discs are partially roughened at their periphery. Furthermore at certain distances from one another cut-outs are provided at the periphery into which the material to be comminuted is drawn so that it is also torn in the transverse direction by being overstretched. There then arise relatively long, narrow particles.
It has already been proposed to construct the comminution rolls with cutting discs in the form of saw-plates i.e. with a saw toothing with each tooth having an essentially radial edge and an edge running out at a relatively flat angle. This relatively flat saw toothing in which the tooth pitch i.e. the distance of the apices from one another amounts to a multiple of the tooth height, was provided predominantly for better gripping of the material to be comminuted and the maximum intersection of the two outer circles of the cutting discs was likewise a multiple of the tooth height. With this apparatus, in which the cutting discs are not synchronised relative to one another, material to be comminuted is comminuted in undefined fashion.
The devices in accordance with the state of the art have a very substantial energy requirement and this not only during the cutting process but also when running empty.